Resistance heated funnel



c. M. DE WOODY ETAL 2,979,594

RESISTANCE HEATED FUNNEL April 11, 1961 Filed Feb. 2, 1960 INVENTORCHARLES M. D8 WOOD) ROSCOL L PE ARGE ATTORNEY RESISTANCE HEATED FUNNELCharles M. De Woody and Roscol L. Pearce, Vineland, 'NJ., assignors toAce Glass Incorporated, Vineland, N.J., a corporation of New JerseyFiled Feb. 2, 1960, Ser. No. 6,302

'11 Claims. c1. 219-49 This invention relates to funnels and the likefor laboratory and similar uses and consists more particularly in newand useful improvements in a glassware funnel having integrated heatingmeans.

Frequently, in the use of funnels and similar articles of laboratoryequipment formed of glass and like materials, it is desirable andsometimes necessary to control the temperature and viscosity of thematerials being handled. The application and maintenance of a controlleduniform temperature in funnel-like structures has presented aconsiderable problem which has created a 'rial to thereby facilitateconvenience in use.

' Still another object of the invention is to provide an electricalresistance coating for glassware funnels, the width and arrangement ofsaid coating being variable to meet the conditions to be maintained andthe particular materials being handled. I

A further object of the invention is to provide a simple and expedientmeans for heating a glassware funnel while suspended from supportingelectrodes.

With the above and otherobjects in view which will appear as thedescription proceeds, the invention consists in the novel featuresherein set forth, illustrated in the United States Patent accompanyingdrawings and more particularly pointed 'out in the appended claims.

Referring to the drawings in which numerals of like Fig. 2 is a similarview partially broken away, taken 9 from the opposite side ofthe funnel,and

Fig. 3 is a bottom view of the funnel shown in Fig. l. Briefly, theinvention consists in applying to the outer elevation showing one sideof Patented Apr. 11, 1961 In the drawings, 5 generally represents afunnel of the present invention comprising the usual flaring body 6, thewalls of which converge and terminate in an elongated stein 7. The outerperiphery adjacent the mouth of the flaring body 6 is provided with apair of terminal strips 8 and 9, preferably formed by coating thesurface of the body 6 with a film of silver which is baked on the funnelbody. The terminal strips 8 and 9 are separated from one another on oneside of the body 6 by a radially projecting clear glass knob orenlargement 10, formed on the body 6 which, as will later appear, servesthe added function of facilitating the location of the supportingelectrodes. On the other side of the body 6, the terminalstrips 8 and 9are separated by a space of clear glass 11, as seen in Fig. 2.

- 'A band of electrical resistance material 12, preferably comprising acoating of platinum applied to the outer periphery of the funnel,extends in a helical path from adjacent the upper end of the body 6where it contacts the terminal strip 8, to the lower end of the steam 7where it contacts a silver connecting band 13 which also may be in theform of a coating applied to the stem 7. The convolutions of the band 12are separated from one another by a helical space or gap 14 whichcontinues at the upper end of the body 6 where it merges with an annularspace 15, separating the resistance band 12 from the terminal strip 9.

1 The circuit is completed by providing a helical current conductingreturn band 16, connected at its upper end to the terminal strip 9 andfollowing the path of the helical gap 14 to its lower end where it is inelectrical contact with the connecting band 13. Thereturn band 16 ispreferably formed of the same material as the terminal strips 8 and 9and is applied in the form of a coating directly on the surface of theglass funnel, the coating being spaced from the opposed boundaries ofthe gap 14 so as to be completely isolated from the convolutions ofresistance coating 12.

In a companion application Serial No. 862,331, filed December 28, 1959,we described and illustrated a combined support-clamp and electricalconnecting device for use with a generally similar heating unit. Thisdevice comprises a body portion adapted to be connected into a suitableelectrical'outlet and provided with a pair of arcuate electrodes forengaging complementary contacts on the unit to be heated. The funnel ofthe present invention is designed for use with a similar combinedsupportclamp and electrical connecting device and to this end, the upperportion of the-funnel body 6 is provided with a pair of annular ribs 17fused to the body and spaced a short distance from the flaring upperextremity thereof. Thus, as shown in Fig. 2, in dotted lines, theelectrodes 18 of the 'connecting'device engage the flaring periphery ofthe body 6 immediately above the respective ribs 17, in electricalcontact with the terminal bands 8 and 9.

I The electrodes 18 thereby support the funnel proper and periphery of aglassware funnel, a film or coating of re- 'sistance material, arrangedin a relatively wide spiral band, connected atits upper end to one of apair of terminal strips, and at its lower end to a connecting band ofconducting material. The spiral band of resistance material is soarranged that its convolutions are spaced from one another a distance toaccommodate a narrow intervening, spaced conductor band which likewisefollows a helical path, said conductor band being connected at its upperend tothe other-of said pair of terminal strips and at its lower end tosaid connecting band. Thus, the application of electrodes to said pairof terminal strips causes electrical current to how around the funnelthrough said resistance band and return through the,interveningconductorband in a complete circuit.

at the same time energize the terminal bands 8 and 9.

Preferably, although not necessarily', the ribs 17 are included in thesilver coated area of the respective terminal bands 8 and 9. Also, whileI have described the terminal bands 8 and 9 and the return band 16 asformed of silver, it will be understood that they may be formed of othersuitable conducting materials or they may be of the same material as theresistance coating 12.

The resistance coating 12 has been described as preferably composed ofplatinum but it may be stated that various other metals, such as silver,tin, aluminum and gold may be employed. The platinum coating ispreferably applied by spraying and baking in an oven at temperatures inexcess of 1100 F. and the thickness of the coating may vary butgenerally should not exceed .0015 inch and should not be less than0.0003 inch. The thickness of the terminal bands and the return band maybe of a thickness in the order of .008 inch and not less than .003 inch.

The present invention atfords maximum control of the surface to beheated and by varying the distance between the convolutions of the band12 at the top and bottom of the funnel, the effective heat can beselectively distributed.

It will be apparent that the principle of the present invention maybeapplied with equal effect to various types of funnels includingseparatory funnels or in fact, to any similar tapered article ofglassware or the like where it is desired to control the temperature andviscosity of materials being handled.

From the foregoing, it is believed that my invention may be readilyunderstood by those skilled in the art without further description, itbeing borne in mind that numerous chan es may be made in the detailsdisclosed without departing from the spirit of the invention as setforth in the following claims.

We claim:

1. A unit of glassware or the like, having a helical.

coating band of electrical resistance material applied to its periphery,the convolutions of said band being spaced by a helical non-conductinggap, a pair of separate terminal strips applied to the surface of theupper end of said unit, one of said terminal strips being in electricalcontact with the adjacent extremity of said coating band, a connectingband applied to the surface of the lower end of said unit in electricalcontact with said coating band, and a helical circuit completing bandlying within said non-conducting gap, its lower end contacting saidconnecting band and its upper end contacting the other of said pair ofterminal strips.

2. A unit of glassware or the like, having a helical coating band ofelectrical resistance material applied to its periphery, theconvolutions of said band being spaced by a helical non-conducting gap,a pair of separate terminal strips comprising coatings of electricalconducting material applied to the surface of the upper end of saidunit, one of said terminal strips being in electrical contact with theadjacent extremity of said coating band, a connecting band comprising acoating of electrical conducting material applied to the surface of thelower end of said unit in electrical contact with said coating band, anda helical circuit completing band comprising a coating of electricalconducting material applied to the sur face of said unit within saidnon-conducting gap, its lower end contacting said connecting band andits upper end contacting the other of said pair of terminal strips.

3. A funnel of glassware or the like, having a helical coating band ofelectrical resistance material applied to its periphery, theconvolutions of said band being spaced by a helical non-conducting gap,a pair of separate terminal strips comprising coatings of electricalconducting material applied to the surface of the upper end of saidfunnel, one of said terminal strips being in electrical contact with theadjacent extremity of said coating band, a connecting band comprising acoating of electrical conducting material applied to the surface of thelower end of said funnel in electrical contact with said coating band,

and a helical circuit completing band comprising a coating of electricalconducting material applied to the surface of said funnel within saidnon-conducting gap, its lower end contacting said connecting band andits upper end contacting the other of said pair of terminal strips.

4. A funnel as claimed in claim 3, wherein said coating band, terminalstrips, connecting bands and circuit completing band comprise coatingsof. noble metal applied directly to the surface of said funnel.

5. A funnel of glassware as claimed in claim 4, wherein the coatingsforming said terminal strips, connecting band and circuit completingband are of lesser resistance than said helical coating band ofresistance material. I a a 6. A funnel of glassware or the like, havingan electrical resistance band of platinum applied to its periphery inhelical form, the convolutions of said band being spaced by a helicalnon-conducting gap, a pair of separate terminal strips comprisingcoatings of silver applied to the surface of the upper end of saidfunnel, one of said terminal strips being in electrical contact with theadja-, cent extremity of said coating band, a connecting band of silverapplied to the surface of the lower end of said funnel in electricalcontact with said coating band, and a helical circuit completing band ofsilver applied to the surface of said funnel within said non-conductinggap, its lower end contacting said connecting band and its upper endcontacting the other of said pair of terminal strips.

7. A funnel as claimed in claim 6, wherein said helical coating band isgradually reduced in width from the top to the bottom of said funnel. v

8. A funnel of glassware or the like, comprising a flaring bodyterminating in a reduced stem, a helical coating band of electricalresistance material applied to the surface of said body and stem, theconvolutions of said band being spaced by a helical non-conducting gap,a pair of separate terminal strips comprising coatings of electricalconducting material applied to the surface of said body adjacent itsflaring end, one of said terminal strips being in. electrical contactwith the adjacent extremity of said coating band, a connecting bandcomprising a coating of electrical conducting material applied to thesurface of the lower end of said stern in electrical contact with saidcoating band, a helical circuit completing band comprising a coating ofelectrical conducting material applied to the surface of said body andstem within said non-conducting gap, its lower end contacting saidconnecting bandand its upper end contacting the other of said pairofterminal strips, and a pair of radially projecting ribs formed on thesurface of said body adjacent-said terminal strips, in spaced relationto the extremity of the flaring end of said body. to facilitate theapplication of electrodes to respective terminal strips.

9. 'A funnel as claimed in claim 8, wherein adjacent ends of saidterminal strips are separated by clear glass areas of said body.

10. A funnel as claimed in claim 9, including a radial projection ofglass adjacent one of said spaced areas,'for locating a supportingelectrode device.

11. A heated funnel assembly comprising a funnel of giassware'or thelike, having a helical coating bandof electrical resistance materialapplied to its periphery, the

convolutions of said band being spaced by a helical nonconducting gap, apair of separate terminal strips comprising coatings of electricalconducting material applied to the surface of the flaring upper end ofsaid funnel, one of said strips being in electrical contact with the ad-'jacentextremity of said coating band, a pair ofsradially projectingribs integrated with the periphery of said funnel in spaced relation toits flaring end and. adjacent said terminal strips, supportingelectrodes engageable ,with said terminal strips in abutment with saidribs, a

connecting band comprising a coating of electrical con- References Citedin the file of this patent UNITED STATES PATENTS 897,782 Reilley Sept.1, 1908 1,920,629 Chevassus Aug. 1, 1933 1,978,089 Jones Oct. 23, 19342,701,296 Crawford Feb. 1, 1955 2,915,613 Norton Dec. 1, 1959

